Toroidal electromagnetic device



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United States Patent TOROIDAL ELECTROMAGNETIC DEVICE Carl E. Coy, Glen Burnie, Md., and Byrl D. Tague, Indianapolis, Ind., assignors to the United States of America as represented by the Secretary of the Navy Filed Oct. 11, 1955, Ser. No. 539,955

1 Claim. (Cl. 336-107) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to toroidal electromagnetic devices and particularly to a plug-in type of toroidal electromagnetic device that is adaptable for use with printed circuitry.

Heretofore it has been the common practice in making toroidal coils to solder pigtails to the end of the windings to provide a suitable connection thereto. This method of making toroidal coils has several disadvantages and the completed coils also were not readily adaptable for mounting. Heretofore when windings were first started around the core the inner ends had to have leads soldered thereto so that an electrical connection could be made to these inner ends. These lead wires, which might be five or six in number would interfere with the winding of the resistance wire and constant attention was required to keep them straight and free from the windings. The outer ends of the resistance wire were also connected to pigtails, as by soldering, thus producing a coil that had ten or twelve loose connections, Although the pigtails were usually color-coded, the hook-up of a coil required considerable time and attention to make certain that the coil was properly connected. Also there was no convenient method of mounting the completed coils and usually some elaborate device was required to secure the toroidal coils to an assembled unit.

The present device overcomes the heretofore mentioned difiiculties of manufacture and provides a completed unit that is readily assembled to a terminal board or other unit. A plurality of prongs are embedded in the cover of a core box and the winding ends are connected thereto. The completed unit can be plugged into a circuit as readily as a tube. The use of prongs eliminates the need for pigtails and the windings can readily be wrapped around the core box and between the prongs. It is therefore a general object of the present invention to provide a toroidal electromagnetic device that is easily fabricated and that can be readily mounted in a circuit.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

Fig. 1 is atop plan view of a core box showing a prong arrangement;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1; and

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Fig. 3 illustrates in a cross-section an electromagnetic device.

Referring now to the drawing, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Figs. 1 and 2, a core 11 of soft iron composition mounted within a core box 12, which is made of electrically non-conductive material. A cover 13, which also is made of electrically non-conductive material, fits the core box 12 and thus the core 11 of soft iron composition is completely surrounded by non-conductive material.

A plurality of prongs 14 are secured to the cover 13, as for example by being molded integral therein, and these prongs 14 can be so arranged that the unit is polarized and can be mounted in only a single position. One end of a winding 15 of small diameter wire is attached to one of the prongs 14 as by looping several turns of wire around the prong and soldering thereto, and then the required number of turns of the winding are wound around the core box and cover, and between the prongs 14. The remaining end is then fastened to a different prong 14. This procedure is the same for the additional windings and it can be seen that the completed unit can readily be plugged into a circuit or socket.

In Fig. 3 of the drawing there is shown a cross-section of a completed toroidal coil wherein the windings 15 are shown being insulated from the iron core 11 by the core box 12 and cover 13.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described.

What is claimed is:

A toroidal electromagnetic device comprising: a toroidal core assembly constituted by a core box having a uniform cross-section of electrically non-conducting material, said box having an inner and outer coaxial cylindrical wall, said walls being connected by an integral hollow cylindrical ring extending from. said inner wall to said outer wall thereby enclosing one end of the hollow cylindrical space between said inner and outer walls, a core of soft iron disposed completely within said core box in the hollow cylindrical space formed by the said outer and inner walls, a separable hollow circular ringshaped core box cover of electrically non-conducting material to cover said core of soft iron and having a plurality of metallic prongs attached thereto and extending outwardly therefrom in parallel relationship to the axis of said toroidal core assembly and to each other; and a plurality of small diameter wires wound about said toroidal core assembly and between said prongs, the end portions of said wires being connected to at least two of said prongs to provide a plug-in unit.

References Cited in the file of this patent UNITED STATES PATENTS 1,548,388 Schackelton Aug. 4, 1925 1,763,115 Wermine June 10, 1930 2,290,680 Franz July 21, 1942 2,425,443 Soreng Aug. 12, 1947 2,434,511 Osterman et al. Jan. 13, 1948 2,437,513 Gethmann Mar. 9, 1948 2,455,355 Combs Dec. 7, 1948 2,471,869 Gebel May 31, 1949 2,869,089 Hampel Jan. 13, 1959 

